1. Field of the Invention
The present invention relates to a terminal holding member, and, in particular, to a terminal holding member having a tubular shape and including an accommodation portion into which an electroconductive member is inserted. The present invention also relates to a clamping device including the terminal holding member and the electroconductive member.
2. Description of the Related Art
For example, a terminal holding member is used as a connection terminal of a busbar of a joint box. With the terminal holding member, a mating terminal can be inserted into a gap formed by an accommodation portion of the terminal holding member and an electroconductive member inserted into the accommodation portion. When the mating terminal is inserted into the gap, the terminal holding member can hold the mating terminal and the electroconductive member together.
Japanese Unexamined Patent Application Publication No. 63-289779 describes such a terminal holding member and an example of a clamping device including the terminal holding member and an electroconductive member. FIG. 21 is a perspective view of a terminal holding member 112 and an electroconductive member 110 disclosed in Japanese Unexamined Patent Application Publication No. 63-289779. FIG. 22 is a sectional view of a clamping device including the terminal holding member 112 and the electroconductive member 110.
The terminal holding member 112, which is made by punching and bending a single electroconductive metal plate, has a flat tubular shape as a whole and includes an accommodation portion extending through the center thereof. The accommodation portion includes a flat plate portion 112a, a pair of spring contact portions 112b for holding a plate-shaped portion 111 from both sides of the flat plate portion 112a, and a pair of press spring portions for fixing the terminal holding member 112 to the plate-shaped portion 111. The electroconductive member 110 is inserted into the accommodation portion beforehand. The electroconductive member 110 has an L-shape in a side view and includes the plate-shaped portion 111, which is inserted into the accommodation portion of the terminal holding member 112. The plate-shaped portion 111 has a rib 111a at the center thereof.
After the plate-shaped portion 111 has been inserted into the accommodation portion, a mating terminal 113 is inserted into a gap between the accommodation portion and the plate-shaped portion 111. The terminal holding member 112 can elastically hold both the plate-shaped portion 111 and the mating terminal 113 together. In particular, the terminal holding member 112 elastically holds the plate-shaped portion 111 and the mating terminal 113 by pressing the mating terminal 113 toward the plate-shaped portion 111 by using thickness portions of the pair of spring contact portions 112b and a pair of press spring portions 112d and in the longitudinal direction along the rib 111a. 
However, in the existing technology described above, the terminal holding member 112 elastically holds the plate-shaped portion 111 and the mating terminal 113 by using the thickness portions of the pair of spring contact portions 112b and the pair of press spring portions 112d, which are very thin plate-shaped members, and in a narrow region extending substantially in the width direction of the rib 111a. As a result, the existing technology has a problem in that the mating terminal 113 cannot be sufficiently pressed against the plate-shaped portion 111. When the mating terminal is not sufficiently pressed against the electroconductive member, a high contact resistance is generated between the mating terminal and the electroconductive member. In particular, when the terminal holding member is used to pass a comparatively large electric current, serious problems, such as overheating and fire, might occur.